Analysis of Lymphoid Cells Responding to Virus- and Tumor- Associated Antigens in Spleens of Syngeneic Mouse Mammary Tumor Systems With Low and High Oncogenic Potentials 1,2,3

ABSTRACT-Nylon-nonadherent cells obtained from the spleens of tumor bearers of two BALB/c mouse colonies with different oncogenic potentials were found to be the lymphocyte subclass responsive in blastogenesis to their tumor-associated antigens (TAA), Thus Thy 1-positive spleen cells from BALB/cCrgl mice that received implants of a syngeneic, chemically induced mammary tumor and BALB/cfC3H mice bearing spontaneous mammary tumors (SMT) incorporated high levels of [3H]thymidine after in vitro exposure to homologous TAA preparations. These responses were evident in animals at the early stages of tumorigenesis but could not be detected in the T-cells of animals with large tumor burdens. Responses to murine mammary tumor virus (MuMTV) antigens were observed likewise in the nylon-nonadherent spleen cell population of the MuMTV-positive BALB/ cfC3H mice bearing small SMT. The responsiveness to viral antigens also decreased with progression of the disease, In BALB/cCrgl mice